This invention relates to a safety release closure suitable for use in a mass transit vehicle which can be rapidly and conveniently removed either toward the inside or the outside of a vehicle with little or no danger of the closure becoming wedged or otherwise jammed in the surrounding support structure.
As disclosed in U.S. Pat. Nos.: 3,927,492; 3,806,188; 3,739,527, many emergency windows that are used today in mass transit vehicles are designed to open in one direction upon a fixed hinge or pivot mechanism. Gernerally, to prevent injury to the passengers, the window is caused to swing outwardly or away from the passenger compartment. This necessitates that a protruding and generally unsightly hinge be mounted along at least one margin of the window sash. More importantly, the hinged, one-way window is highly susceptible to failure in case of an accident. The hinge can become damaged to a point of failure or the surrounding supporting structure can be pushed against the window to prevent it from swinging in an outward direction.
As further disclosed in U.S. Pat. No. 2,572,124 some emergency windows are constructed without hinges and are arranged to be removed either to the inside or outside of the vehicle. The emergency window, in this case, is supported in the frame by means of wedge strips that can be pulled free to release the window sash from the supporting frame. Here again, however, the window can become wedged within the frame if it is not pulled therefrom in a direction that is generally perpendicular to the frame. Any deviation from this critical path of travel will tend to turn the sash obliquely within the frame, thus causing it to jam. The natural tendency in an emergency situation is to apply greater pulling force against the jammed sash. This, of course, is counterproductive and usually results in the sash becoming inextricably bound to the frame.